function showSection(id){
	var divs=document.getElementsByTagName("div");
	for(var i=0;i<divs.length;i++){
		if(divs[i].className.indexOf("section")==-1) continue;
		if(divs[i].getAttribute("id")!=id){
			divs[i].style.display="none";
		}else{
			divs[i].style.display="block";
		}
	}
}

function prepareInternalnav(){
	if(!document.getElementsByTagName) return false;
	if(!document.getElementById) return false;
	if(!document.getElementById("internalnav")) return false;
	var nav=document.getElementById("internalnav");
	var links=nav.getElementsByTagName("a");
	for(var i=0;i<links.length;i++){
		var sectionId=links[i].getAttribute("href").split("#")[1];
		if(!document.getElementById(sectionId)) continue;
		document.getElementById(sectionId).style.display="none";
		links[i].destination=sectionId;
		links[i].onclick=function(){
			showSection(this.destination);
			return false;
		}
	}
}